The subdivision of medical practice called nuclear medicine has developed rapidly, primarily through the availability of imaging devices such as scanners, and particularly the Anger camera, the latter often associated with a computer. Such imaging devices are generally costly, large, have limited flexibility, can not be relocated readily, and can form images of internal organs only by detecting radiation which has passed through intervening tissue to reach a detector located outside the body which is being examined. Such intervening tissue scatters the nuclear radiation rays and thus degrades the image, reduces the signal-to-noise ratio by adding extraneous rays which appear to come from the area in question, and enforces, by its physical bulk, a more distant view to be taken. In addition to these disadvantages, the relationship of the area of interest to the rest of the body may prohibit a view being obtained at all, owing to the bulk and inflexibility of the currently used external detectors. Additionally, further degrading of the image results from respiratory and other motions of the imaged body organs.
Prior art devices have been used to optically view internal organs (U.S. Pat. Nos. 3,253,524; 3,799,150 and 3,799,151), and there have been suggestions to detect the presence or absence of ionizing radiation with a device implanted or otherwise introducted into an animal body. However, while optical two-dimensional images of examined organs have been obtained by such prior art devices, and while there have been suggestions that it is possible to detect the presence or absence of nuclear radiation at a location inside an animal body, it has not been possible prior to this invention to obtain a two-dimensional nuclear radiation image at a location inside an animal body and to view or otherwise utilize a representation of such two-dimensional image at a location outside the body.